Keeping a car’s battery charged is the job of an alternator. Without this key piece of equipment, the battery would die after only a short amount of driving. In order for the alternator to keep charging, it will have to continue to spin. This spinning is made possible by the belt that runs from the pulley on the alternator to the crankshaft. The belt does a very specific job and without it, the alternator will not be able to provide the constant charge the battery needs when the car is running.
The longer that the same alternator belt is on the car, the higher the risk will be that it has to be replaced. The type of belt around your alternator will depend solely on the make of your vehicle. Older cars will use a V-belt for the alternator while newer cars will use a serpentine belt.
1. Battery light is on
When the battery light on your instrument cluster comes on, you will need to pay attention. While this light does not tell you exactly what is wrong with your car’s charging system, it is the first line of defense in getting the issues addressed. Taking a look under the hood is the best way to see if a broken alternator belt is the cause of the battery light being turned on.
2. Dimming or flickering interior lights
The lights on the inside of your car are used primarily during the nighttime hours. When there are problems with the charging system, these lights will usually flicker or become very dim. A broken belt will prohibit the alternator from doing its job and can be the cause of the lights on the interior of your car becoming dim or flickering. Replacing the belt is essential in restoring the lights back to normal.
3. Engine stalls
Without a properly working alternator and alternator belt, the power that the car needs will not be supplied. This means that when the battery dies out, the car will be rendered unusable. Having this happen on the side of a busy road or highway can create a lot of problems. Getting the alternator belt replaced is the only way to get the car back on the road quickly.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Alternator Belt and was authored by Ed Ruelas.